Rapidity dependence of antideuteron coalescence in pp collisions at $\sqrt{s}$ = 13 TeV with ALICE

TL;DR

This study measures antideuteron and antiproton production in proton-proton collisions at 13 TeV, analyzing how their coalescence probability varies with transverse momentum and rapidity, providing data relevant for cosmic ray antinuclei flux predictions.

Contribution

First rapidity-differential measurement of antideuteron production and coalescence parameter in pp collisions at 13 TeV, extending understanding of antinuclei formation mechanisms.

Findings

Measured spectra of antideuterons and antiprotons as functions of pT and rapidity.

Extracted and analyzed the rapidity dependence of the coalescence parameter B2.

Provided extrapolated models for B2 at higher pT and rapidity regions.

Abstract

The production yields of antideuterons and antiprotons are measured in pp collisions at a center-of-mass energy of $\sqrt{s}=13$ TeV, as a function of transverse momentum ($p_{\rm T}$) and rapidity ($y$), for the first time rapidity-differentially up to $|y|= 0.7$. The measured spectra are used to study the $p_{\rm T}$ and rapidity dependence of the coalescence parameter $B_2$, which quantifies the coalescence probability of antideuterons. The $p_{\rm T}$ and rapidity dependence of the obtained $B_2$ is extrapolated for $p_{\rm T}> 1.7$ GeV/$c$ and $|y|>0.7$ using the phenomenological antideuteron production model implemented in PYTHIA 8.3 as well as a baryon coalescence afterburner model based on EPOS 3. Such measurements are of interest to the astrophysics community, since they can be used for the calculation of the flux of antinuclei from cosmic rays, in combination with coalescence models.